Oral health remains a global problem. Mental has been related to oral behavior. However, studies among adolescents in high-income countries are limited. This study aimed investigate the association of adolescents' mental and well-being with regular toothbrushing. We used data from 2018 Luxembourg Health Behavior School-Aged Children ( n = 7,561; 3,896 [51.5%] girls; mean [standard deviation] ag...